The invention is a device for preventing theft of a towed trailer vehicle and, more specifically, a security device which is mounted to the end portion of the tongue of the trailer in spaced relation to the socket lock mechanism for the towing ball and is adapted to lock over the socket lock mechanism to prevent the detachment of an attached trailer vehicle.
The theft of trailer vehicles is a wide spread problem. Since most recreational vehicles are transported by trailer it is becoming increasingly common for unauthorized persons to steal these trailers by simply connecting their towing vehicle to the trailer hitch ball sockets and drive off with the recreational vehicles as mounted or stored on the trailer since they are often left unattended and unguarded for long periods of time.
Commonly, the trailer hitch coupling is not provided with a lock which will prevent unauthorized opening of the hitch mechanism and removal of the trailer from the draft vehicle. The prior art has disclosed the use of pad locks and special locks to attempt to provide a degree of security but these simple devices are no match for a thief with the proper tools to destroy or manipulate the lock to easily obtain access to the trailer and its cargo of recreational vehicles.
The prior art discloses selective inadequate solutions to similar problems. For example, Callison, U.S. Pat. No. 4,774,823, discloses the use of an external padlock construction attached to the underside of the tongue which provides a cover guard and is secured by a padlock to the tongue of the hitch to cover the conventional socket to which a ball of a trailer hitch on the towing vehicle attaches to prevent theft of an unattended trailer. To use the device, some modifications of the trailer tongue or coupler is needed, and the cover guard may need to be re-contoured to fit certain couplers. Unfortunately, the padlock offers little security against the use of a hacksaw to quickly remove the keeper member.
Dolan et al., U.S. Pat. No. 5,154,440, discloses a locking mechanism for a trailer coupler having a release handwheel to force the ball firmly into the socket. A retaining shelf formed with two openings, is hingedly attached to the trailer tongue and pivots the end portion to receive the periphery of the user manipulated handwheel to cover the ball. When the retaining shelf is pivoted, a locking flange attached to the tongue moves through a locking flange aperture so that a padlock may be attached through a locking aperture in the locking flange to secure the retaining shelf in place. The padlock is completely exposed and accessible for easy access and manipulation as set forth above.
Completely enclosing the ball socket has been attempted in the past. For example, Foster, U.S. Pat. No. 3,605,457, discloses a trailer hitch lock wherein a housing is arranged to enclose the ball socket and outer portions of the trailer hitch. The housing consists of a cover which is enclosed on the bottom by a base plate and a lock plate. A substrate towing ball is carried by the base plate with side plates welded thereto. The substrate towing ball is arranged for insertion into the ball socket of the hitch. Both the base plate and lock plate are moveable relative to the housing to allow the apparatus to be secured and removed from the hitch. The cover is pivotally mounted to the base plate. The lock plate holds a lock assembly to secure the pivotable cover to the housing side walls.
This type of trailer hitch lock obviously has very limited applications since today most ball elements of a hitch are permanently fixed to the tongue so that the trailer hitch lock of Foster could not be used since it allows no opening in the housing for a ball that is not removable from the tongue.
Utman et al., U.S. Pat. No. 3,924,878, also disclosed a protective housing and padlock assembly for shielding a standard trailer coupler and protecting the padlock from excessive exposure to weathering and highway abrasions. The Utman et al. invention provides for a protective housing characterized as having a base plate portion and a cover plate portion defining a hollow structure open at one or both of its ends for being engaged over and around a trailer coupler and a padlock assembly associated therewith. The associated padlock assembly may comprise a separate standard padlock or a padlock incorporated into the assembly of the protective housing means. The hollow structure may be formed as an integral rigid structure from steel or other known materials which offer desired protection. The protective housing means includes a cutout slot formed in the forward edge of its base plate portion and extending rearwardly along the base plate portion for a sufficient distance to allow the protective housing to be slidably engaged and fitted over a variety of sizes and forms of standard couplers with the base plate portion being received under an actuating lever assembly associated with such standard couplers. The protective housing means further includes a bearing block or post rigidly affixed in its hollow interior to engage and fix the position of a sliding locking bar (which may be part of a standard bicycle lock) of the padlock assembly. The bearing block or post further functions to guide a U-shaped shackle portion of the padlock assembly into locking engagement with its locking bar portion. The arrangement is such that the movable portion of the padlock assembly fixes and secures the protective housing in place while it is carrying out its usual function of securing the lever arm of the coupler, and thus, no additional locking devices and keys are required for the use of the protective housing means.
Unfortunately, the protective housing of Utman et al. is bulky and complicated, as well as requires extensive rework of the tongue of the trailer in order to accommodate the welded construction of the housing and insure its proper functioning with the standard ball and socket arrangement. It is also subject to the same limitations as those described above with respect to the use of a padlock which is easily violated.
Accordingly, what is needed is a protective housing for shielding the standard trailer coupler which is simple to operate, adapts to all standard ball and socket arrangements including the socket lock mechanism to allow unobstructed access to secure the trailer to the hitch bar, does not require extensive rework of the tongue of the trailer, has adequate securing means, and is low cost and is constructed of few parts.